java - 当我的动态壁纸超过 30 帧时出现内存不足错误

Question

我一直在尝试用开机动画制作一个简单的动态壁纸。所以基本上我的可绘制文件夹中有大约 50 个 .png。我可以将动画设置为大约 10-20 帧，效果很好。但是一旦我将其设置为大约 30 帧...我就会收到 OutOfMemory 错误。我希望也许有人可以看一下我的代码，并举例说明如何实现更多框架？这会有很大帮助，我已经研究了几个小时了> <

这是我的代码:

package com.androidnetwork.animlivewp;

import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.os.Handler;
import android.os.SystemClock;
import android.service.wallpaper.WallpaperService;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;

public class AnimatedLiveWallpaper extends WallpaperService {

    private final Handler mHandler = new Handler();

    @Override
    public void onCreate() {
        super.onCreate();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    @Override
    public Engine onCreateEngine() {
        return new CubeEngine();
    }

    class CubeEngine extends Engine {

        private final Paint mPaint = new Paint();
        private float mPosY;
        private boolean mAnime = true;
        private Matrix mMatrix = new Matrix();

        private final Runnable mDrawAnim = new Runnable() {
            public void run() {
                drawFrame();
            }
        };
        private boolean mVisible;

        private static final int NUM_RES = 30;
        private final Bitmap[] mPics = new Bitmap[NUM_RES];
        CubeEngine() {
            Resources res = getResources();
            for (int i = 0; i< NUM_RES; i++) {
                int id = res.getIdentifier("boot_00" + (100 + (i + 1)), "drawable", "com.androidnetwork.animlivewp");
                mPics[i] = BitmapFactory.decodeResource(res, id);
            }
        }

        @Override
        public void onCreate(SurfaceHolder surfaceHolder) {
            super.onCreate(surfaceHolder);

            setTouchEventsEnabled(false);
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            mHandler.removeCallbacks(mDrawAnim);
        }

        @Override
        public void onVisibilityChanged(boolean visible) {
            mVisible = visible;
            if (visible) {
                drawFrame();
            } else {
                mHandler.removeCallbacks(mDrawAnim);
            }
        }

        @Override
        public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            super.onSurfaceChanged(holder, format, width, height);

            float w = mPics[0].getWidth();
            float h = mPics[0].getHeight();
            float s = width / (float)w;
            mMatrix.reset();
            mMatrix.setScale(s, s);

            mPosY = (height - (h * s)) / 2f;
            drawFrame();
        }

        @Override
        public void onSurfaceCreated(SurfaceHolder holder) {
            super.onSurfaceCreated(holder);
        }

        @Override
        public void onSurfaceDestroyed(SurfaceHolder holder) {
            super.onSurfaceDestroyed(holder);
            mVisible = false;
            mHandler.removeCallbacks(mDrawAnim);
        }

        @Override
        public void onOffsetsChanged(float xOffset, float yOffset,
                float xStep, float yStep, int xPixels, int yPixels) {
            drawFrame();
        }


        @Override
        public void onTouchEvent(MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_MOVE) {
                mAnime = !mAnime;
            }
            super.onTouchEvent(event);
        }


        void drawFrame() {
            final SurfaceHolder holder = getSurfaceHolder();

            Canvas c = null;
            try {
                c = holder.lockCanvas();
                if (c != null) {
                    // draw something
                    drawAnim(c);
                    //drawTouchPoint(c);
                }
            } finally {
                if (c != null) holder.unlockCanvasAndPost(c);
            }

            // Reschedule the next redraw
            mHandler.removeCallbacks(mDrawAnim);
            if (mVisible && mAnime) {
                mHandler.postDelayed(mDrawAnim, 1000 / 10);
            }
        }


        private int idx = 0;
        void drawAnim(Canvas c) {
            c.save();
            c.translate(0, mPosY);
            c.drawBitmap(mPics[idx], mMatrix, mPaint);
            if (mAnime) ++idx;
            if (idx == NUM_RES) idx = 0;

            c.restore();
        }



    }
}

如果有帮助的话，这里有一个 logcat:

08-22 19:45:05.508: ERROR/AndroidRuntime(12277): FATAL EXCEPTION: main
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277): java.lang.OutOfMemoryError: bitmap size exceeds VM budget
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.Bitmap.nativeCreate(Native Method)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.Bitmap.createBitmap(Bitmap.java:468)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.Bitmap.createBitmap(Bitmap.java:435)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.Bitmap.createScaledBitmap(Bitmap.java:340)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.BitmapFactory.finishDecode(BitmapFactory.java:488)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:462)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:323)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:346)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:372)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at com.androidnetwork.animlivewp.AnimatedLiveWallpaper$CubeEngine.<init>(AnimatedLiveWallpaper.java:55)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at com.androidnetwork.animlivewp.AnimatedLiveWallpaper.onCreateEngine(AnimatedLiveWallpaper.java:32)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.service.wallpaper.WallpaperService$IWallpaperEngineWrapper.executeMessage(WallpaperService.java:814)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at com.android.internal.os.HandlerCaller$MyHandler.handleMessage(HandlerCaller.java:61)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.os.Handler.dispatchMessage(Handler.java:99)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.os.Looper.loop(Looper.java:123)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at android.app.ActivityThread.main(ActivityThread.java:4627)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at java.lang.reflect.Method.invokeNative(Native Method)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at java.lang.reflect.Method.invoke(Method.java:521)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
    08-22 19:45:05.508: ERROR/AndroidRuntime(12277):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

每次绘制 Canvas 时，仅创建一个位图并重新加载每个 png。例如，创建一个简单的例程，将每个图像重新加载到相同的位图分配中。我还建议您将 png 文件转换为 jpg 文件，因为 png 是无损格式。使用 jpg，您可以稍微压缩每一帧。

public void updateBG() {

idx += 1;
if (idx == NUM_RES) {idx = 0;}
switch (bgcycle) {
    case 0: myBg = BitmapFactory.decodeResource(getResources(),R.drawable.frame1); break;
    case 1: myBg = BitmapFactory.decodeResource(getResources(),R.drawable.frame2); break;
    case 2: myBg = BitmapFactory.decodeResource(getResources(),R.drawable.frame3); break;
            case etc....
        }}

或者我想如果你想链接到启动动画，你可以使用这个

int id = res.getIdentifier("boot_00" + (100 + (idx + 1)), "drawable", "com.androidnetwork.animlivewp");
            myBg = BitmapFactory.decodeResource(res, id);

然后在您的 DrawAnim 代码中

updateBG();
c.drawBitmap(myBg, mMatrix, null);